An exemplary surgical instrument comprises a handpiece, an end effector, and an activation and control feature that is operable to selectively activate an end effector and select an energy level for the end effector. One version of the activation and control feature includes a “floating” button feature where activation and control is accomplished based on the displacement of the button from a home position. In some versions the activation and control feature is sealed within the handpiece, but controllable by the users touch with the handpiece. The sealed configuration can allow the handpiece to be sterilizable, e.g., using steam sterilization. The activation and control feature may comprise capacitive switches, resistive sensors, resonant cavity switching technology, infrared sensing technology, technology that uses a resonant standing wave on a surface that is perturbed by the presence of a finger, and/or any other suitable type of technology.